<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    text-transform,文本转换<br>
    所有字母大写：uppercase<br>
    <span>the time is now</span><br>
    <span id="upWord">the time is now</span>
    <style>
        #upWord{
            text-transform: uppercase;
        }
    </style>
</body>
</html>